cppdoubles 0.4.0

New features

• get_tolerance and set_tolerance as helpers to get/set the package-wide
  tolerance.

• New argument scale added to rel_diff to allow users to optionally
  specify a scale for each relative difference.

Changes

• The default argument for tol now uses get_tolerance().

Internal updates

• Inlined most of the simple C++ functions which provides some moderate
  speed improvements.

• Some C++ functions were returning double when they should return bool. This
  has now been fixed.